3 Hardware Description
Note 1:
»Configuration via Serial Port« is only effective on port 1 of the NetCom
+
Server.
Note 2:
Factory Settings are restored on Power-Up/Reset of the NetCom
+
.
Note 3:
The Master DIP switches configure all serial ports of a NetCom
+
to a common
operation mode. If diversity in line operation modes is intended, the switch must
be set to »Selected by Software«, and the configuration may be done via Serial
Port, Telnet, Web browser or SNMP.
Note 4:
Line operation modes of RS 422 and RS 485 are not available on NetCom Plus
111 / 211 / 411 / 811 (incl. POE).
Note 5:
In RS 485 mode the NetCom
+
performs the required activation and disabling of
the RS 485 transmitter by an internal automatic. Application software does not
have to perform special operations.
USB–COM Plus modules may be added for port expansion. These are either configured by their
own DIP switches. Or when the 4- and 8-port modules are set for configuration by software, the
operation mode is controlled by the NetCom Plus in the same way as with the internal ports.
3.2 Serial Signal Assignment
It is of course important to know the exact location of the serial signals in the configured mode.
Here is the table for the DSub-9 male connector. For RS 232 the assignment is the same as on any
PC (Com1/2).
Pin
RS 232
RS 422 / 485 4-wire
RS 485 2-wire
1
DCD
Tx
−
(A)
Data
−
(A)
2
RxD
Tx+ (B)
Data+ (B)
3
TxD
Rx+ (B)
4
DTR
Rx
−
(A)
5
GND
GND
GND
6
DSR
7
RTS
8
CTS
9
RI
Table 16: Signal Assignment DSub-9 male
Figure 10: Connector
DSub-9 male
Please note the GND signal in RS 422 and RS 485 modes. This signal must also be connected be-
tween the serial devices. So in reality there is neither a 2-wire nor a 4-wire connection. With the ex-
ception of very special configurations, a serial cable without GND violates the specifications for RS
422 and RS 485. Signal RI is only available in RS 232 mode on NetCom Plus 111 /113 / 211 / 213.
On USB–COM Plus modules used for Port Expansion the signal assignment is the same as on
NetCom Plus. Also signal RI is only available with one and two ports.
September 2016
NetCom Plus User Manual
23